A long-term comparison of tacrolimus (FK506) versus cyclosporine in liver transplantation. A report of the United States FK506 study group

Background. The long-term (5 year) efficacy and safety of tacrolimus (FK506) and cyclosporine were compared in primary liver transplant recipients who participated in a 1-year randomized, multicenter trial and a 4-year follow-up extension study. Methods. A total of 529 patients (263 tacrolimus group, 266 cyclosporine group) were randomized to study drug. Patients were evaluated at 3-month intervals. Patient and graft survival rates, incidence of adverse events, and changes in laboratory and clinical profiles were determined. Results. Cumulative 5-year patient and graft survival rates were comparable for the tacrolimus (79.0%, 71.8%) and cyclosporine (73.1%, 66.4%) groups. However, patient half-life survival was longer for tacrolimus- treated patients (25.1±5.1 years versus 15.2±2.5 years; P=0.049). Improved patient survival with tacrolimus was also observed for hepatitis C-positive patients (78.9% tacrolimus group versus 60.5% cyclosporine group; P=0.041). Both treatments were associated with a low incidence of late acute rejection, late steroid-resistant rejection, and death or graft loss related to rejection. Both treatments demonstrated an acceptable safety profile with maintenance of adequate renal and liver function and a low incidence of malignancy/lymphoproliferative disease and serious infections. Conclusions. Tacrolimus is a safe and effective long-term maintenance immunosuppressive agent in primary liver transplantation.